Ive got an Ipod touch right (don't know if its 2g or 3g), jail broken and currently on 3.1.2 and im thinking about updating the firmware and re jail breaking it. But i have heard that Ios4 isn't good, that its slow, that it dies easily so i figured that i would ask people that i trust a little more.

Is it good or bad?

P.S the only reason i feel like updating is because im getting sick of Itunes constantly saying there is a new version available every time i plug it in on a new user or on my mum's mac.